Speaking personally...
The best quality ships out there in terms of detail and production are NinjaMagic, but they are relatively expensive.
The ones link by Mal - "Otterman" are looking nice and the Homeworld ships he has look very nice.
Zandris are excellent - well made and cast, but not as exactly detailed as NinjaMagic...you can make a nice single fleet and they paint up lovely.
GZG are amongst the very best of the "Hand-made" ships (i.e. not done by 3D) alongside Zandris...massive choice, free rules and ongoing deveolpment and new ships on a regular basis.
Spartan's Firestorm ships I dont rate, (they can never seem to make their own minds up whether they are any good or not, and as with their rules, appear to change them every 4-6 months and the designs are lifeless.)
Some of the Cold Navy ships are very nice, but i cant seem to find many of them...in some cases perhaps too much detail on some ships also.
Odyssey Slipways do the very best Star Wars ships, but will be very expensive...but OMG a fleet by the would be nice - they also need more ships in the range.
I just bought the GZG Neu Swabian and ConFed fleets as I think they are good looking and the best detail for the price.
Given a bigger wallet though I would go with NinjaMagic on one side and Homeworld on the other: so Zandris IV and the odd ship here and there by others like Otterman.
However, all said and done: When I get the time I will simply make my own fleets in a Homeworld style...which, on current form, will be around 3030.
